Plastic closure

ABSTRACT

The invention relates to a plastic closure ( 1 ) having a bottom part ( 2 ) and a top part ( 3 ) in order to make a tubular bag ( 4 ) user-friendly and provide it with a secure closure. The bottom part ( 2 ) has a flange ( 20 ) on which a nozzle ( 21 ) is integrally formed. The nozzle has a cylindrical part ( 22 ), in the region of which a form-fit means ( 25 ) is attached to one side and an external thread ( 26 ) located above is attached to the other side. A tapering, arched, conical part ( 23 ) follows over the cylindrical part. The top part ( 3 ) consists of a retaining ring ( 30 ), which is connected to a cap ( 40 ) via a tightening strap ( 31 ). The retaining ring ( 30 ) comprises form-fit means ( 33 ) which engage with the form-fit means ( 25 ) on the cylindrical part ( 22 ) of the nozzle. The retaining ring ( 30 ) is thus held on the nozzle ( 21 ) in a rotatable but axially fixed manner. The cap ( 40 ) has an internal thread ( 48 ) which clamps with the external thread ( 26 ) of the nozzle ( 21 ).

BACKGROUND OF THE INVENTION

The present invention relates to a plastic closure for use on a tubular bag having a dispensing opening and comprising a bottom part having a nozzle, which is arranged over the dispensing opening, and a top part having a cap for a tight closure of the nozzle.

A large number of tubular bags is present on the market today, said tubular bags however being predominately produced from multilayered films, particularly from such films which at least comprise a layer of paper, a layer of plastic as well as a layer of aluminum. Said tubular bags are relatively pressure-resistant and are predominately cubically designed.

Tubular bags, which consist only of plastic film, have, however, been on the market for some years. Such tubular bags are particularly used as refill bags for cosmetics. Tubular bags, which are manufactured from pure plastic films, usually have no closure at all and merely a portion of the tubular bag is cut away for dispensing purposes, and the content of the tubular bag is poured into a container. Tubular bags made from plastic are alternatively available, which have a flange comprising a pouring nozzle and a plain screw cap mounted on the latter. Because, as already mentioned, said tubular bags have to be opened and closed only once or in any case only a few times, only screw closures are used for the most part. Plastic closures consisting of a bottom part having a nozzle and a cap connected to the bottom part via a hinge are available on the market in any number of variants; however, the mounting of said closures on tubular bags is out of the question. Tubular bags made from plastic are highly flexible and hence relatively large forces, which lead to the deformation of said tubular bags and thus raise the internal pressure, act on said bags during transport and handling. Pure hinge closures are not capable of withstanding these forces. For safety reasons, only plastic closures of the kind mentioned at the beginning of the application have therefore been mostly used to date on tubular bags.

SUMMARY OF THE INVENTION

The applicant is currently bringing only tubular bags consisting of pure plastic film onto the market, said bags being suited to be a drink receptacle. This suitability as a drink receptacle requires that such tubular bags are equipped with a plastic closure, which comprises a hinge closure for quick opening and closing. Said hinge closure is however adapted in such a way that it can also withstand high pressures without losing any closing force in the process. This aim is met by a plastic closure, which is thereby characterized in that the cap can be directly connected to the nozzle so as to be movable in a screw-like fashion and is indirectly held pivotably on the nozzle so as to be able to be opened and closed.

The nozzle is preferably designed as a drink nozzle comprising a cylindrical part, to which a tapering, convexly conical part attaches, wherein the cylindrical part is furnished with a flange suited for connecting to the tubular bag. Such drink nozzles are known as bottom parts to plastic bottles and do not then have a flange for an adhesive or welded connection to a tubular bag.

In principle, it would also be conceivable to connect the cap directly to the nozzle or the flange of the bottom part via a relatively long, so-called slack strap. Such straps merely ensure loss protection but do not have an effect on the closing motion. It is therefore proposed in this case to connect the cap to a retaining ring via a tightening strap, said retaining ring being held on the cylindrical part of the nozzle in a rotatable and axially fixed manner.

It is particularly advantageous for the plastic closure according to the invention to be designed such that when the cap has been completely screwed open, the lower edge of the cap ends up in the region in the proximity of the transition from the tapered into the convexly conical part of the nozzle. This solution is then particularly advantageous if during the opening screwing motion of the cap, the tightening strap moves from an approximately stretched, non-tensioned position into a completely stretched, tensioned position. If the pivoting motion is now carried out, the lower edge of the cap is now guided along the tapered, convexly conical part of the nozzle along a generating line of this rotational body, wherein a snap movement of the cap is achieved during opening and closing.

BRIEF DESCRIPTION OF THE DRAWINGS

In the attached drawings, a preferred exemplary embodiment of the inventive subject matter is depicted and subsequently described.

In the drawings:

FIG. 1 shows a tubular bag comprising a plastic closure according to the invention in the closed state.

FIG. 2 shows an identical tubular bag comprising the same plastic closure in the open state.

FIG. 3 shows the bottom part of the plastic closure, half of which is in sectional view and the other half in side view, whereas

FIG. 4 shows the top part of the plastic closure according to the invention in the manufacturing position, wherein the retaining ring is depicted in cross-section and the cap is depicted half in sectional view and half in side view.

FIG. 5 shows the plastic closure according to the invention on its own in the open state.

DETAILED DESCRIPTION

The plastic closure is labeled in its entirety with the numeral 1. Said plastic closure consists of a bottom part 2, which is mounted on a tubular bag 4 and a top part 3 which can be connected to the bottom part 2.

The tubular bag 4 shown here consists of a pure plastic film and is implemented here as a tubular bag having a gabled roof. The plastic closure can, of course, be mounted on other tubular bags independently of the form and material selection thereof. Said plastic closure according to the invention is however suited and designed to be mounted on tubular bags made from relatively highly flexible materials in order to ensure that the closure does not open by itself as a result of high internal pressure.

The tubular bag has a dispensing opening 5 which is stamped into the film of the tubular bag 4. The bottom part 2 is correspondingly aligned such that it relatively exactly comes to rest over said opening and is either adhesively bonded or welded to the film. In the event a welding connection is to be implemented, the bottom part is provided with appropriate welding conductive elements 24.

The bottom part 2 of the plastic closure 1, which is depicted in detail in FIG. 3, consists substantially of a circumferential, annular flange 20 which comprises the aforementioned welding conductive elements 24 on the bottom side thereof. A nozzle 21 extends from the flange 20 up to the drinking orifice 28. Said nozzle 21 is designed in this case as a drink nozzle. Said nozzle 21 comprises a lower cylindrical part, which is the first directed upwardly from the flange and to which a tapering, arched, conical part 23 attaches. A circumferential form-fit means 25 is molded into or integrally formed with the cylindrical part 22 of said nozzle 21. This circumferential form-fit means can, for example, be a retaining groove, as depicted here in FIG. 3, or, for instance, a circumferential retaining bead at the same location. Especially if a retaining bead is used, said retaining bead can be divided up into partial sections so that said bead is not designed as a continuous profile.

An external thread runs above the circumferential form-fit means 25 but still in the region of the cylindrical part 22 of the nozzle 21. This external thread 26 can comprise a single thread turn, which runs relatively flatly and extends around approximately 360E, or a plurality of shorter threaded sections, which are designed correspondingly steeper, and therefore the same travel is achieved using a smaller torsion angle.

An upwardly tapering, arched and therefore also conical part 23 attaches above the cylindrical section 22. This part 23 of the nozzle represents that part which the user guides into or to his or her mouth when drinking The upper edge of the conical part 23 is equipped with a closing bead, which serves substantially to protect the user from injury. The nozzle, which is open on the top, comprises accordingly a drinking orifice 28. The drinking orifice 28 has preferably a circumferential, annular sealing wall which is pulled down toward the inside and the bottom. Said sealing wall 29 interacts with the cap 40 via a corresponding seal.

The so-called top part is depicted on its own in FIG. 4 in a completely open form corresponding to the manufacturing position. The top part consists substantially of three elements, namely on the one hand of a retaining ring 30 and on the other hand of a cap 40, wherein both parts are connected to one another via a third element, namely a tightening strap 31. Instead of one single tightening strap, two tightening straps 31 can be used which run parallel to one another and are disposed relatively close to one another, with which a somewhat increased locking effect is achieved when opening and closing the closure.

The retaining ring 30 consists substantially of a cylindrical ring wall 32. Said cylindrical ring wall 32 is not as tall as the cylindrical part 22 of the nozzle 21. The retaining ring 30 typically covers approximately 50-75% of the cylindrical part 22 of the nozzle 21. On the inside of the cylindrical ring wall 32, a circumferential form-fit means 33, which in this case is implemented as a retaining bead, can be seen. Said retaining bead 33 is shaped like a saw tooth in cross section. The corresponding circumferential form-fit means 25 on the bottom part 2 is correspondingly designed in cross section in a mirror-inverted manner. The form-fit means 25 and 33 can, of course, also be interchanged as previously described, i.e. a corresponding groove could be introduced on the inside of the retaining ring and a circumferential bead could be located accordingly on the cylindrical part 22 of the nozzle 21. Said retaining bead could also have in this case a saw tooth-like cross section. Because the wall thickness of the nozzle 21 is normally greater than the wall thickness of the retaining ring 30, the arrangements of the retaining means as depicted here are thus chosen.

A recess 34 introduced in the cylindrical ring wall 32 can furthermore be seen on the retaining ring 30. Diametrically opposed to the recess 34, a point of attachment 35, whereat the aforementioned tightening strap 31 engages, is integrally formed on the outside of said retaining ring 30. In the proximity of the point of attachment 35, said tightening strap 31 can additionally be equipped with a film hinge 36. In the same manner, said tightening strap 31 is in turn integrally formed on the cap 40 via a point of attachment 35 and also in this case, a corresponding film hinge can be present.

The cap 40 of the top part 3 has a casing side 41, which basically can be designed purely cylindrically; however, in this case matches somewhat the shape of the nozzle for esthetic purposes, wherein said casing side transitions into a top surface 42. On the inside of said top surface 42, a wall 43 projecting annularly and vertically therefrom can be seen. Said wall represents a seal which accordingly effects a sealing contact with the inside of the sealing wall 29 of the nozzle 21 while protruding into the orifice 28 thereof when the closure is closed. This type of seal is known in the trade language as a sealing olive. Said seal is accordingly arched on the outside or provided with appropriate sealing lips.

It is however important for the cap 40 to be provided with an internal thread 48 on the inside of the casing side 41. In so doing, the cap 40 becomes a screw cap although the top part in its entirety forms a hinge closure. Said hinge closure has a cap and a closing bottom part that is designed as a retaining ring 30, said bottom part being however connected to the cap 40 via the tightening strap 31.

A tamperproof element 45 in the form of a plate 45 is integrally formed with the bottom edge 47 of the casing side 41 via predetermined breaking point bridges 44. A tear-off tab 46 is molded as one piece with said tamperproof element or respectively plate 45. The plate 45 comprises in turn a part of a form-fit means on an interior side thereof, said form fit-means engaging into the corresponding form-fit means 25 of the bottom part in the assembled state of the closure.

When mounting the closure according to the invention, the top part, which is manufactured in the manner depicted in FIG. 4, is initially closed, i.e. the cylindrical ring wall 32 of the retaining ring 30 comes to rest flush under the bottom edge 47 of the cap 40 and is subsequently placed onto the bottom part 2. Said bottom part 2 can already have been welded to a tubular bag that is still empty or can also be placed together with the already mounted top part 3 onto the empty tubular bag and be adhesively bonded or welded thereto.

When opening the closure according to the invention, the cap 40 is first turned, the retaining ring 30 turning with said cap at the same time. When turning in this manner, said cap 40 executes an axial movement while the retaining ring 30 does not move axially at all. The tightening strap 31 is thus completely stretched and tensioned. If this screwing motion of the cap has been executed, the bottom edge 47 of the case siding 41 of said cap 40 comes to rest approximately at the height of the transition of the cylindrical part 22 to the tapering, arched, conical part 23. Prior to this, the breaking points 44 were however already destroyed with the aid of the tear-off tab and therefore the plate 45 has been torn off so that a form-fit connection between the cap 40 and the bottom part 2 no longer exists. In principle, the cap can also, however, be opened without the tamperproof element being previously torn off. This is the case because the relative axial movements between said cap 40 and the retaining ring 30, which thereby occur, are sufficient to destroy the breaking point bridges 44. This action does however require a greater application of force. In both cases, the plate will however fall off and the tamperproof element has performed the safeguarding function thereof.

After completing the screwing movement with the cap 40, said cap can be easily swiveled. In the region diametrically opposed to the tamperproof element, the bottom edge 47 can therefore slide along a generating casing line of the nozzle 21 in the tapering, arched, conical part 23 along said nozzle. In so doing, a controlled opening operation takes place while at the same time the tightening strap 31 becomes practically a part of a snap-type hinge, i.e. a closure having a virtual, shifting axis of rotation.

When closing the closure according to the invention, the reversed sequence of the previously described opening movement takes place.

As a result of this unusual combination, diverse advantages are achieved. If the inventive closure is initially assembled prior to being mounted on the tubular bag as previously described and is subsequently welded onto the tubular bag which is not yet a completely finished product, said tubular bag can then be subsequently filled and finally be closed by a weld so that an aseptic filling of said tubular bag can be guaranteed. Furthermore, a consumer obtains a tubular bag having a closure, which on the one hand withstands high internal pressures and on the other hand also facilitates a desired drinking comfort as well as a reliable reclosing of the bag. When drinking, it is sufficient to merely flip the screw cap open and closed. If, however, the not completely empty tubular bag is to be transported or stored in the refrigerator, the consumer should execute the screwing movement so that the safe position is achieved. The closure according to the invention thus combines in a perfect way a conventional screw closure with a known snap-type hinge closure. 

1. A plastic closure (1) for application on a tubular bag (4) having a dispensing opening (5), the closure comprising a bottom part (2) having a nozzle (21) which is disposed over the dispensing opening and a top part (3) having a cap (40) for tight sealing of the nozzle (21), characterized in that the cap (40) can be directly mounted on said nozzle (21) so as to be movable in a screw-like fashion and is indirectly held pivotably on said nozzle (21) so as to be able to be opened and closed.
 2. The plastic closure (1) according to claim 1, characterized in that the nozzle (21) is a drink nozzle comprising a cylindrical part (22), to which a tapering, arched, conical part (23) attaches, wherein the cylindrical part (22) is provided with a flange (20) configured to connect to the tubular bag.
 3. The plastic closure (1) according to claim 2, characterized in that the cap (40) is connected via a tightening strap (31) to a retaining ring (30) which is held on the cylindrical part (22) of the nozzle (27) in a rotatable and axially fixed manner.
 4. The plastic closure (1) according to claim 3, characterized in that the retaining ring (30) is not as tall as a height of the cylindrical part (22) of the nozzle (21) in an axial direction.
 5. The plastic closure (1) according to claim 2, characterized in that an external thread (26) is integrally formed with an upper region of the cylindrical part (22) of the nozzle and the cap (40) has an internal thread which is matched thereto.
 6. The plastic closure (1) according to claim 3, characterized in that the retaining ring (30) is connected by means of a circumferential form-fit means (33) onto a corresponding mirror-inverted form-fit means (25) on the cylindrical part (22) of the nozzle (21) in an axially fixed manner, but rotatably to said nozzle.
 7. The plastic closure (1) according to claim 3, characterized in that the tightening strap (31) moves from an approximately stretched position into a completely stretched, tensioned position when the cap (40) is being screwed open.
 8. The plastic closure (1) according to claim 7, characterized in that after the cap (40) has been completely screwed open, a bottom edge (47) of said cap (40) ends up at least in a region in the proximity of the transition from the cylindrical part (22) into the tapering, arched, conical part (23) of the nozzle (21).
 9. The plastic closure (1) according to claim 6, characterized in that a tamperproof element (45) is integrally formed with the cap (40), the element engaging in the circumferential form-fit means of the nozzle in a tamperproof position.
 10. The plastic closure (1) according to claim 9, characterized in that the tamperproof element (45) is a plate, which is connected to the cap (40) via breaking point bridges (44).
 11. The plastic closure (1) according to claim 9, characterized in that the retaining ring (30) comprises a recess which extends in an assembled state from top to bottom across the form-fit means on the nozzle (21) and corresponds at least to the size of the plate (45).
 12. The plastic closure (1) according to claim 9, characterized in that a tear-off tab (46) is molded to the plate (45).
 13. The plastic closure (1) according to claim 3, characterized in that the retaining ring (30) is connected by means of a circumferential form-fit retaining bead onto a corresponding mirror-inverted form-fit means (25) on the cylindrical part (22) of the nozzle (21) in an axially fixed manner, but rotatably to said nozzle.
 14. The plastic closure (1) according to claim 3, characterized in that the retaining ring (30) is connected by means of a circumferential form-fit means retaining groove onto a corresponding mirror-inverted form-fit means (25) on the cylindrical part (22) of the nozzle (21) in an axially fixed manner, but rotatably to said nozzle. 